Medicare Part A Trust Fund Depletion Projected for Q2 2033, One Quarter Earlier Than Prior Estimate
核心洞察
The Medicare Hospital Insurance trust fund is now projected to be depleted in the second quarter of 2033, one quarter sooner than last year's estimate, driven by softer payroll growth and revised health cost assumptions.
At depletion, incoming payroll taxes would still cover approximately 89% of scheduled Part A benefits, translating to an estimated 11% cut in hospital payments that could grow to 16% by 2040.
Medicare Part B (搜索) and Part D are funded through the Supplementary Medical Insurance program and face no comparable depletion risk, as they draw on beneficiary premiums and general federal revenues adjusted annually.
The Medicare Trustees released their annual report on June 9, 2026, projecting that the Medicare Hospital Insurance (Part A) trust fund will be depleted in the second quarter of 2033 — one quarter earlier than the third-quarter 2033 estimate issued in last year's report. The accelerated timeline is primarily attributed to updated estimates of Social Security tax revenue that are lower than previously projected, partly due to changes enacted in the 2025 budget reconciliation bill.
The Hospital Insurance trust fund, which pays for inpatient hospital services, skilled nursing facility care, hospice, and some home health benefits, is funded almost entirely by the 2.9% payroll tax split between employers and employees, plus a 0.9% additional Medicare tax on higher earners. When the trustees refer to "depletion," they mean accumulated reserves will be exhausted while incoming payroll taxes continue to flow.
At the projected depletion point, incoming payroll taxes are still expected to cover approximately 89% of scheduled Part A benefits. Outside analysts translate this into an initial 11% reduction in hospital payments, which could grow to roughly 16% by 2040 if Congress takes no action. "That is a meaningful squeeze on hospitals and skilled nursing facilities, while scheduled benefits continue at 89 cents on the dollar," the report's analysis indicates.
Part B and Part D Remain on Different Financial Footing
Unlike Part A, Medicare Part B (搜索) (physician services, outpatient care, durable medical equipment) and Part D (prescription drugs) are funded through the Supplementary Medical Insurance (SMI) program, which draws revenue from beneficiary premiums and general federal revenues. The SMI program is financed each year to meet expected costs rather than relying on a dedicated trust fund balance, meaning neither Part B nor Part D faces a comparable depletion event.
The standard Part B premium has risen to $202.90 per month in 2026, with premiums and federal funding adjusted annually to support expected spending. The same basic framework applies to Part D.
Medicare Spending Landscape in 2025
Total Medicare benefit payments reached $1.2 trillion in 2025, up from $666 billion a decade earlier. Spending on Part B services — including physician services, outpatient services, and physician-administered drugs — accounted for the largest share at 48%. Part A services represented 37% of benefit spending, a decline from 43% in 2016, driven partly by the shift of services from inpatient to outpatient settings and increases in high-cost physician-administered drugs.
Part D prescription drug spending accounted for 15% of Medicare benefit spending in 2025, up from the 12-13% range maintained over much of the prior decade. The Trustees project Part D spending will nearly double from $181 billion in 2025 to $346 billion in 2035, representing an average annual growth rate of 6.7% — significantly higher than the 4.8% projected last year. The Trustees attribute this to increased use of GLP-1s and other high-cost specialty drugs, along with policy changes including the pharmacy price concessions policy, expanded orphan drug exemptions from price negotiation, and the redesigned Part D benefit structure.
Medicare Advantage Growth Continues
Payments to Medicare Advantage plans under Part A and Part B reached $534 billion in 2025, representing 53% of total Medicare program spending. This nearly tripled as a share of total Part A and Part B spending from $189 billion in 2016. Enrollment in Medicare Advantage plans rose from 33% to 54% of all eligible beneficiaries over the same period.
Medicare pays an estimated 14% more per enrollee in Medicare Advantage than it would if the same beneficiary were covered by traditional Medicare, resulting in $76 billion in additional Medicare spending in 2026. Growth in Medicare Advantage spending is projected to continue, with payments expected to reach $1.3 trillion in 2035, or 59% of total Part A and Part B spending.
Implications for Beneficiaries
Part A cost-sharing in 2026 includes a $1,736 inpatient deductible per benefit period, $434 per day in coinsurance for days 61 through 90, $868 per day for lifetime reserve days, and $217 per day for skilled nursing days 21 through 100. If the trust fund were depleted without congressional action, analysts expect the pressure to fall primarily on provider payments rather than beneficiary benefits, though the exact outcome would depend on how policymakers respond.
The practical concern for beneficiaries centers on access: hospitals, skilled nursing facilities, and other providers facing lower reimbursement could become more selective about Medicare patients or reduce services in some markets. Historically, Congress has enacted reforms that improved the fund's finances and pushed depletion dates further into the future, typically acting within two years of a projected depletion date.